- #1
veronicak5678
- 144
- 0
Homework Statement
A well insulated cup contains 125 g of water at 23 degrees. How many grams of ice must be added to lower temp to 12?
Homework Equations
Q = c*m*delta t
The Attempt at a Solution
energy needed to lower temp:
Q = 4190 J / kg * (-11 degrees) * (.125 kg) = -5760 J
Q from ice = - Q from water = 5760 J
to find mass of ice needed:
5760 J = Latent heat of ice * mass needed = (3.34 * 10^5 J / kg) * m
= .0172 kg = 17.2 g
The correct answer is 15 g. What am I doing wrong?